1. Field
The invention relates to a gas exchange membrane for a medical application, in particular for use in an artificial lung. The invention further relates to a method for the production of a gas exchange membrane of this type.
2. Background
Gas exchange media of this type are for instance disclosed in EP 0 765 683 B1, in EP 0 803 259 A1, in DE 42 38 884 A1, in DE 600 03 112 T2 and in DE 100 34 098 A1. The gas exchange membrane is applied in an oxygenator in order to transport oxygen to blood or blood plasma and in order to remove carbon dioxide, which is produced by metabolic activity, from the blood or blood plasma. The gas exchange membrane is in particular known in the form of a hollow fiber membrane. In conventional oxygenators, the hollow fibers are for instance made of polypropylene (PP) or of polymethylpentene (PMP). Both materials are polymers of the polyolefins and have poor blood compatibility. When these materials are used, an activation of the blood coagulation system, primarily of the thrombocytes, can be observed. Moreover, defects or leaks in the known hollow fibers may cause blood or blood plasma to escape from the blood circulation of the oxygenator, with the undesirable result that blood or blood plasma reaches the non-sterile side of the gas exchange membrane. Due to the limited gas exchange performance of conventional hollow fiber membranes, conventional oxygenators are quite voluminous. The disadvantage of the large volume of conventional oxygenators is that a considerable amount of blood or blood plasma needs to be provided for the exchange of gas. Gas exchange membranes are also used in other medical applications, for instance as pads for the treatment of burns.
EP 0 754 488 describes gas separation membranes, for instance for medical applications.
JP 2004/050042 A describes a membrane module of a silicone foam for gas separation.
DE 100 12 308 A1 describes hollow fiber membranes which are both applicable for gas exchange and for separation processes. The hollow fibers are spun. The disclosure suggests a method of producing cells by adding foaming agents.
WO 99/38604 A1 discusses several disclosures which have dealt with the fabrication of open-cell and closed-cell membranes.
WO 02/04554 A1 describes a gas- or liquid-permeable bicontinuous foam structure.
WO 00/26006 A1 describes a method of producing microcellular foams for the production of molded articles.